Optimizing the ASME Venturi Recovery Cone Angle to Minimize Head Loss

Abstract

Many flow-meter applications require accurate flow measurement (0.5% of actual flow or better), whereas other applications accept less-accurate flow measurements. Some applications attempt to minimize head loss, whereas a few applications have ample energy such that a flow meter with higher head loss is preferred. In many instances where highly accurate flow measurement and low head loss are required, Venturi flow meters are a viable option. The accuracy of a Venturi for flow measurement is well established and well documented; however, the design of recovery cones and their associated head loss is not. This study uses computational fluid dynamics and laboratory data to demonstrate the relationship between recovery cone angle on the classical Venturi meter design and associated head loss. Results from this study show that the optimum recovery cone angle to minimize head loss is a function of beta ratio and Reynolds number. Whereas Venturi codes provide ranges of acceptable cone angles, this research provides the optimal recovery cone angle to minimize permanent pressure loss.